Molecular structure in correlation with electrochemical properties of mixed-ligand cobalt(III) complexes

Four mixed-ligand cobalt(III) complexes (1-4) of the general formula (Co(Rdtc)cyclam)(ClO4)2 and (Co(Rac)cyclam)(ClO4)2 (cyclam = 1,4,8,11-tetra- azacyclotetradecane; Rdtc = thiomorpholine-(Timdtc) or 2-methylpiperidine- -(2-Mepipdtc) dithiocarbamates; Rac = 1,1,1,5,5,5-hexafluoro-2,4-pentanedio- nato (Hfac) or 2,2,6,6-tetramethyl-3,5-heptanedionato (Tmhd), respectively) were electrochemically examined on a glassy carbon and an iron electrode in perchlo- ric acid solution. The obtained results showed the influence of these complexes on hydrogen evolution, the oxygen reduction reaction and iron dissolution. The exhibited effects of the complexes on these reactions depend on structure rela- ted to the bidentate dithiocarbamato or β-diketonato ligand. The electrochemical properties of the complexes were correlated with molecular structure and para- meters derived from spectral analysis and molecular modeling.